慢性反復性心室性頻拍症の1学童例—プログラム刺激法と心内膜マッピングによる発生機序の解明

Recurrent sustained ventricular tachycardia in a school boy

　小児期における心室性頻拍症は比較的稀な疾患であり，成人^1〜3）と異なり器質的疾患を基盤とするものは少ない。私達は器質的心疾患のない12歳男児における慢性反復性心室性頻拍症（recurrent sustained ventricular　tachycardia以下VTと略す）の1例を経験し，プログラム刺激法と心内膜マッピングの施行によりその発生機序の解明を試みたので報告する。

A case of recurrent sustained ventricular tachycardia in a 12 year old boy with duration of more than 3 months was reported. No organic heart disease was found by thorough noninvasive and invasive investigations. The electrocardiogram demonstrated an abnormal QRS configuration of RBBB pattern, and ventricular rate was 150 beats per minute.

Programmed stimulation and endocardial map-ping were performed. The results were 1) ventri-cular tachycardia was initiated and terminated by extrastimulus method, 2) no consistent retrograde His bundle deflection was noted, 3) there was no correlation between the initiation of ventricular tachycardia and retrograde His-Purkinje conduc-tion delay, 4) rapid atrial and ventricular stimu-lation could activate the ventricle without ter-minating the tachycardia, 5) the earliest site of activation was in the infero-basal region of left ventricle.